Just weeks ago, a suicide bomber detonated an explosive device in the foyer of Manchester Arena, killing 22 Ariana Grande fans and leaving dozens more injured.

That attack followed one on Westminster earlier this year, which saw Winson Green terrorist Khalid Masood plough into pedestrians before fatally stabbing a police officer.

This weekend, London Bridge has been the scene of the latest tragedy, which men brandishing knives making their way to Borough Market, killing seven people and leaving dozens more injured.

Police on Broad Street on Saturday night (Image: SNAPPER SK)

In the wake of the attacks, reports show a reassuringly large number of civilians who resist the bystander effect , offering help and comfort to those who have been injured, the Mirror reports.

Knowing how to help if you're first on the scene of a terrorist attack, in terms of First Aid, is crucial.

So much so, the Joe Mulligan, head of First Aid Education at the Red Cross told the Hippocratic Post : "All the research we have done shows that the first people on the scene are absolutely crucial to the outcome for the victim."

Police officers on the streets of London close to London Bridge where three terrorists attacked on Saturday night

1. Focus on the quiet ones

"People who are injured and making a lot of noise clearly have their airways open," Emma Hammet, a former A&E nurse, first aid trainer, and founder of First Aid for Life told the Post.

"It is the quiet ones who can be slowly slipping away because they are not breathing.

"To check for breathing, ensure that the airway is open by tilting back the head and lifting the chin.

"Spit on the back of your hand and put it close to the victim’s mouth. It will feel cool when breath is expelled.

"Someone should be breathing at least twice in a 10 second period. Don't assume that agonal breathing (the death rattle) is normal breathing. This can be a sign that death is imminent.

"If someone is not breathing, start CPR."

Police on Broad Street on Saturday night (Image: SNAPPER SK)

2. First Aid is a humanitarian and compassionate act

"Cradling injured victims and comforting them is a very important part of first aid – connecting to the injured person," Joe Mulligan adds.

"Reassurance has been shown to be beneficial and improves a person’s chances because stress levels decrease.

"It calms the person and it also gives the first aider valuable thinking time to assess the situation and decide what to do next."

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3. Stabbing and bullet wounds

If the victim is unresponsive and NOT breathing, lie him on his back and make sure his airway is open.

You do this by tilting back the head and pushing up the chin. Start performing CPR.

If the victim is unresponsive but IS breathing, roll them gently into the recovery position.

"Make sure that they are lying on the injured side. This will prevent blood and fluid entering the uppermost lung which is protected by gravity," Emma says.

"If the victim is still upright and moving around, they could collapse at any time due to blood loss, causing further injury.

"Don't remove clothing because they will go into shock due to blood loss and could develop hypothermia.

"Instead, cut or tear clothes so you can see the wounds. Apply pressure to the wounds using your hands or packing material like a scarf or T-shirt."

Going into shock is a real risk for victims with these sorts of injuries, so make sure you keep them warm and as comforted as possible.

Make sure you don't give them anything to eat or drink as they will almost certainly need to go into theatre when admitted to hospital.

Be aware that even a small or barely-visible wound could be indicative of major and fatal internal bleeding.